In recent years, the use of color ink-jet printer and color laser printers has become widespread. A color printer uses a color conversion lookup table to convert input color image data into corresponding amounts of inks of plural colors. In the conventional method for creating a color conversion lookup table, (i) a plurality of sample color patches are printed, (ii) colors of the color patches are measured to obtain their colorimetric values, and (ii) a lookup table that represents correspondence relationships between color patch colorimetric values and the amounts of ink used to print the color patches is created.
However, colorimetric values are dependent upon viewing conditions during color measurement. Accordingly, where a color conversion lookup table has been created so as to give a printout having good color reproduction under a certain viewing condition, it will not necessarily be the case that printouts created using that color conversion lookup table will afford good color reproduction under other viewing conditions. Accordingly, there has for some time existed a need for a color conversion lookup table which enables good color reproduction under various viewing conditions. There has also been a need, when creating a reproduction of a painting or drawing for example, to create a color conversion lookup table that can reproduce as faithfully as possible the color appearance of the original. Such requirements are not limited just to color conversion lookup tables, but are generally desirable in all manner of profiles used for color conversion.